Novel ink-jet app: organ replication

Portland, Ore. - Researchers recently demonstrated a process that one day may enable ink-jet printed human organs to be formed using cells donated by the person receiving the organ, to ensure biocompatibility. The donor's cells would be printed in layers, alternating with structural gels.

The recent experiments, conducted at the University of Missouri (Columbia), involved the use of biological "cues" to enable successful self-assembly of designer tissue. "We can now make three-dimensional hollow biological tubes and organ 'modules,' which could be used as grafts or for doing research," said Gabor Forgacs, a biological physicist at the university. "A fully functional organ is still too complex-but the human body is composed of many hollow tubes like ours."

Forgacs retrofitted an ink-jet printer for his "bio ink," composed of multicellular assemblies, called spherical cell aggregates, that can be printed onto special bio gels. After each layer of cells is printed, an intervening layer of gel is laid down. As a result, the cell aggregates are stacked into a hollow tube configuration. Chemicals are used to coax the cells into fusing into a tube after the gel is dissolved.

"Our next step will be the construction of functional organ modules, prepared outside of a living organism and then implanted into it to prove its biocompatibility," said Forgacs.

Because the organs will be composed entirely of cells from the donor animal, theoretically the body should accept the new organ without all the problems with organ rejection that other techniques must overcome.

The key to Forgac's approach is that there is no need to crack the genetic codes that other researchers are attempting to decode in hopes of growing organs from stem cells. Instead, the correct cell for the job is taken from the donor intact, after which the normal biological mechanisms work to bind the cells together into an organ.

"We provide the proper environment and place the cell aggregates in the correct geometrical shape. After that, the biological system takes over and completes the structure," said Forgacs.

The university is applying for a patent on the bio ink process in preparation for partnering with a commercial company to produce working human organs from donor cells.